Implantable weight control device

ABSTRACT

The present invention provides an endoscopically implantable weight control device that forms a gastric outlet obstruction in a patient&#39;s digestive tract. The weight control device includes an inflatable body residing within the patient&#39;s pylorus and between the stomach and duodenum. The body features a first bulbous portion and a second bulbous portion, the exterior dimensions of the first bulbous portion exceeding the exterior dimension of the second bulbous portion. The body also includes an intermediate portion with exterior dimensions that are less than the exterior dimensions of both the first and second bulbous portions, wherein the intermediate portion resides within the patient&#39;s pyloric valve when the device is implanted. An internal passageway extends through the body, wherein the passageway receives and allows for the passage of chyme from the stomach to the duodenum. A method of treating obese patients with the inflatable weight control device utilizing a sequence of different-sized devices is also provided.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.11/711,364, filed on Feb. 27, 2007, to be issued as U.S. Pat. No.10,235,518, which is incorporated in it's entirety herein by referenceand made a part hereof.

FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

Not Applicable.

TECHNICAL FIELD

The present invention provides an inflatable weight control device thatis implanted with an endoscope. Once inflated, the device is retainedwithin the patient's pyloric valve to form a gastric outlet obstructionwherein chyme can only pass through a central passageway in the deviceto reach the patient's duodenum.

BACKGROUND OF THE INVENTION

According to the Center for Disease Control (CDC), the prevalence ofoverweight and obesity has increased sharply for both adults andchildren over the past 30 years. Between 1976-1980 and 2003-2004, theprevalence of obesity among adults aged 20-74. years increased from15.0% to 32.9%. Among young people, the prevalence of overweightincreased from 5.0% to 13.9% for those aged 2-5 years, 6.5% to 18.8% forthose aged 6-11 years, and 5.0% to 17.4% for those aged 12-19 years.Overweight and obesity ranges are determined by using weight and heightto calculate a number called the “body mass index” (BMI). BMI is usedbecause, fa most people, it correlates with their amount of body fat. Anadult who has a BMI between 25 and 29.9 is considered overweight, whilean adult who has a BMI of 30 or higher is considered obese. Within theobesity category, a person is morbidly obese if he meets one of threecriteria: a BMI over 35, at least 100 lbs. overweight, or 100% aboveideal body weight; and a person is super-obese if he weighs in excess of350 lbs.

It is well recognized that being overweight or obese raises manysignificant health implications. For example, obesity increases the riskof many diseases and health conditions, including: hypertension,dyslipidemia (for example, high total cholesterol or high levels oftriglycerides), type 2 diabetes, coronary heart disease, stroke,gallbladder disease, osteoarthritis, sleep apnea, and respiratoryproblems. In addition to the health implications, overweight and obesityhave a significant economic impact on the U.S. health care system.Medical costs associated with overweight and obesity may involve directand indirect costs. Direct medical costs may include preventive,diagnostic, and treatment services related to obesity. Indirect costsrelate to morbidity and mortality costs, where morbidity costs aredefined as the value of income lost from decreased productivity,restricted activity, absenteeism, and bed days, and mortality costs arethe value of future income lost by premature death. According to a studyof national costs attributed to both overweight (BMI 25-29.9) andobesity (BMI greater than 30), medical expenses accounted for 9.1percent of total U.S. medical expenditures in 1998 and may have reachedas high as $78.5 billion ($92.6 billion in 2002 dollars). Approximatelyhalf of these costs were paid by Medicaid and Medicare. A more recentstudy focused on state-level estimates of the total obesity attributabledirect medical expenditures. State-level estimates range from $87million (Wyoming) to $7.7 billion (California). Obesity-attributableMedicare estimates range from $15 million (Wyoming) to $1.7 billion(California), and obesity-attributable Medicaid expenditures range from$23 million (Wyoming) to $3.5 billion (New York). The state differencesin obesity-attributable expenditures are partly driven by thedifferences in the size of each state's population.

According to the CDC, overweight and obesity are a result of energyimbalance over a long period of time due to a combination of severalfactors. These factors include, individual behaviors, environmentalfactors, and genetics. Energy imbalance results when the number ofcalories consumed is not equal to the number of calories used. When thequantity of calories consumed is greater than calories used, weight gainresults. In the United States and many other highly developed countries,the growing prevalence of pre-packaged foods, fast food restaurants, andsoft drinks, that tend to be high in fat, sugar, and calories, increasea person's calorie consumption. In addition, portion size has alsoincreased which causes people to eat more during a meal or snack,thereby increasing their calorie consumption. If the body does not burnoff the extra calories consumed from larger portions, fast food, or softdrinks, weight gain will likely occur. Despite the well-known benefitsof being physically active, most Americans lead a sedentary life style.According to the Behavioral Risk Factor Surveillance System, in 2000more than 26% of adults reported limited or no physical activity duringthe course of an average week. Regarding the environmental factor,people may make decisions based on their environment or community. Forexample, a person may choose not to walk to the store or to work becauseof a lack of sidewalks. Genetics have been proven to play a role inobesity. For example, genes can directly cause obesity in disorders suchas Bardet-Biedl syndrome and Prader-Willi syndrome. However, genes donot always predict future health; in some cases multiple genes mayincrease one's susceptibility for obesity and require outside factors,such as abundant food supply or little physical activity.

Conventional approaches to combat overweight and obesity have leddoctors to surgically modify patients' anatomies in an attempt to reduceconsumption by inducing satiety or a “full” feeling in the patient,thereby reducing the desire to eat. Examples include stomach stapling,or gastroplasties, to reduce the volumetric size of the stomach. Inaddition, two procedures, the Roux-en-Y gastric bypass and thebiliopancreatic diversion with duodenal switch (BPD), reduce the size ofthe stomach and the effective-length of intestine available for nutrientabsorption. These two procedures reduce the stomach volume and theability of a patient to consume food. In an attempt to limit nutrientabsorption in the digestive tract, at least one company has introduced asleeve that is implanted in obese patients. U.S. Pat. No. 7,025,791discloses a bariatric sleeve that is anchored in the stomach and extendsthrough the pylorus and duodenum and beyond the ligament of Treitz. Allchyme exiting the stomach is funneled through the sleeve and bypassesthe duodenum and proximal jejunum. By directing the chyme through thesleeve, the digestion and absorption process in the duodenum isinterrupted because the chyme cannot mix with the fluids in theduodenum. Because there is no mixing of bile with the chyme until thejejunum, the absorption of fats and carbohydrates is reduced. Althoughthese conventional methods and approaches have had some success, theysuffer from a number of limitations including high correction andmortality rates. Also, conventional methods are costly and prone toadaptation by the patient's digestive tract which reduces theeffectiveness of the method.

Accordingly there is a need for an implantable weight loss device thatis effective in prompting satiety while being minimally invasive and notirritable to patients over time. At the same time, there is a need toprovide a weight control device that can be implanted with an endoscopeduring a visit to a doctor's office, and that does not require ahospital visit. Finally, it would be advantageous to provide treatmentmethods for combating overweight or obesity based upon the weight lossdevice that forms a gastric outlet obstruction in the stomach to promptsatiety and reduce food consumption.

SUMMARY OF THE INVENTION

The present invention provides a weight control device that is implantedand inflated with an endoscope in a patient's digestive track to form agastric outlet obstruction. The weight control device resides within thepylorus and between the duodenum and stomach. The weight control deviceincludes an internal passageway which forms a conduit for the receptionand passage of chyme from the stomach through the pylorus and to theduodenum.

According to one aspect of the invention, the weight control deviceincludes a first bulb, a second bulb, and an intermediate portion whichcollectively define an inflatable body. The internal passageway extendsthrough the body, wherein the passageway receives and allows for thepassage of chyme from the stomach to the duodenum. In a use position,the first bulb engages an inner surface of the pyloric antrum. Thisengagement prevents chyme from passing there between and as a result,chyme must pass through the internal passageway to exit the stomach. Inthe use position, the second bulb engages an inner surface of thepyloric canal, wherein the second bulb resides between the duodenum andthe pyloric valve. Also in the use position, the intermediate portion ofthe body engages an inner surface of the pyloric valve.

According to another aspect of the invention, the collapsed body isinserted through the patient's mouth and through both the esophagus andstomach with the endoscope. A filling tube associated with the endoscopesupplies saline through the valve and into the body until the device issufficiently inflated to form the gastric outlet obstruction. To removean implanted device, the body is deflated, such as by piercing the firstbulb, and the endoscope is used to remove the deflated body.

According to another aspect of the invention, methods of treatingoverweight and/or obesity involve the inventive device. A firsttreatment method involves the staggered implantation of devices havingdifferent sized internal passageways to counter the digestive tract'saccommodation of an implanted device. In a first treatment step, a firstdevice having an internal passageway with a first diameter is implantedwithin the patient's pylorus. When the digestive tract adapts to thefirst device and weight loss stagnates, a second treatment step isemployed. The second treatment step involves the replacement of thefirst device with a second device having an internal passageway that issmaller than that of the first device. While the second device continuesto provide a gastric outlet obstruction in the stomach that blocks thenormal passage of chyme from the stomach and that redirects chyme intothe passageway, the passageway has reduced dimensions that reduce thevolume of chyme that may pass through the device. When the digestivetract adapts to the second device and weight loss again stagnates, athird treatment step is commenced. The third treatment step consists ofreplacing the second device with a third device having an internalpassageway that is smaller than both the first and second devices. Likethe first and second devices, the third device provides a gastric outletobstruction in the stomach that blocks the normal passage of chyme fromthe stomach and that redirects chyme into the passageway. Because lesschyme is able to pass through the passageway of the third devicecompared to the passageway of both the first and second devices, an evengreater amount of chyme accumulates proximate the first bulb and withinthe stomach leading the patient to feel full and stop consuming food.

A second treatment method involves the sequenced use of removableinserts placed within the passageway to counter the digest tract'saccommodation of the device. In a first stage of the treatment method,the device is implanted within the patient's pylorus. When the patient'sdigestive tract begins to accommodate the device and weight lossstagnates, the second stage of the treatment method commences by placinga first insert into the passageway to reduce the diameter of thepassageway. Depending upon whether the digestive track continues toadapt to the device, different sized inserts may be employed to reducethe volumetric capacity of the passageway. As a result, the amount ofchyme that may pass through the device is reduced, which increases theaccumulation of chyme within the stomach, leading the patient to feelfull and stop consuming food.

Other features and advantages of the invention will be apparent from thefollowing specification taken in con junction with the followingdrawings.

BRIEF DESCRIPTION OF THE DRAWINGS

To understand the present invention, it will now be described by way ofexample, with reference to the accompanying drawings in which:

FIG. 1 is a perspective view of a first embodiment of a weight controldevice implanted within a patient's stomach;

FIG. 2 is a perspective view of the weight control device of FIG. 1;

FIG. 3 is a cross-sectional view of the weight control device of FIG. 1,showing an internal passageway of the device;

FIG. 4 is a perspective view of the weight control device of FIG. 1,showing the device in a pre-installed state wherein the device isdeflated;

FIG. 5 is a perspective view of the weight control device of FIG. 1,showing the device during one step of the implantation process;

FIG. 6 is a perspective view of the weight control device of FIG. 1,showing the device during a second step of the implantation process;

FIG. 7 is a perspective view of a second embodiment of a weight controldevice, showing the device having an internal fill valve;

FIG. 8 is a cross-sectional view of the weight control device of FIG. 1,showing a removable insert positioned within the passageway of thedevice;

FIG. 9 is a partial cross-sectional view of a third embodiment of aweight control device, showing a first-sized removable insert positionedwithin the passageway of the device;

FIG. 10 is a partial cross-sectional view of the weight control deviceof FIG. 9, showing a second-sized removable insert positioned within thedevice passageway;

FIG. 11 is a partial cross-sectional view of the weight control deviceof FIG. 9, showing a third-sized removable insert positioned within thedevice passageway;

FIG. 12 is a cross-sectional view of a fourth embodiment of a weightcontrol device, showing the device having two internal passageways;

DETAILED DESCRIPTION

The present invention is not intended to be limited to theabove-mentioned embodiment. It is easily understood for those ordinaryskilled in the art that there are also various modifications oralternatives without departing the conception and principle of thepresent invention. The scope of the present invention is defined by theappended claims.

FIGS. 1-12 depict an inflatable weight control device 10 that isimplanted in a patient's digestive track to form a gastric outletobstruction 19. As explained in greater detail below, an endoscope isused to implant the weight control device 10 within the pylorus A andbetween the duodenum Band stomach C. While the human digestive trackincludes many components, only those that are relevant to the presentinvention are shown in the Figures. The pylorus A is the region of thestomach C that connects to the duodenum B, and that includes threeparts: the pyloric antrum D which connects to the body of the stomach C;the pyloric canal E which connects to the duodenum B; and, the pyloricsphincter or valve F which is a ring of muscle that allows for thepassage of chyme from the stomach C to the duodenum B. Once inflated,the configuration of the device 10 retains it within the pylorus A andprevents unintended movement into the duodenum B or stomach C. Thestomach C consists of four coats or layers: the serous coat, themuscular coat, the areolar or submucous coat, and the mucous membrane,together with an assortment of vessels and nerves. The weight controldevice 10 includes an internal passageway which forms a conduit for thereception and passage of chyme from the stomach through the pyloricvalve and to the duodenum. Chyme is the liquid substance produced in thestomach C before passing through the pyloric valve F and entering theduodenum B. Chyme is highly acidic (a pH value of approximately 2) andconsists of partially digested food, water, hydrochloric acid, andvarious digestive enzymes. In the absence of the inventive device 10,chyme passes through the pyloric valve F and into the duodenum B, wherethe extraction of nutrients begins.

The weight control device 10 includes a first bulbous portion or firstbulb 15, a second bulbous portion or second bulb 20, and an intermediateportion 25. These components collectively define an inflatable body 30with a “dumbbell” configuration. As shown in FIG. 1, the body 30 extendsbetween the pyloric antrum D and the pyloric canal E, and through thepyloric valve F. Unlike conventional weight control devices, such as theelongated sleeve of U.S. Pat. No. 7,025,791 that extends through theduodenum B, the second bulb 20 resides within the pyloric canal E anddoes not extend into the duodenum B. Also unlike the sleeve of the '791Patent, the body 30 has opposed cavities or bulbs 15, 20 that extendfrom a common segment, the intermediate portion 25, and that isinflatable with the endoscope H. In one embodiment, the intermediateportion 25 is semi-rigid compared to the more flexible first and secondbulbs 15, 20, wherein the contractions of pyloric valve F do notcollapse the intermediate portion. To increase the rigidity of theintermediate portion 25, the wall thickness of the intermediate portion25 is greater than that of the first and second bulbs 15, 20. Also, theintermediate portion 25 may be formed from a material with greaterstrength and/or rigidity properties than that used to form the first andsecond bulbs 15, 20. Unlike the sleeve of the '791 Patent, which holdsthe pyloric valve F open to induce a “dumping syndrome,” theintermediate portion 25 is engaged and contracted to a small extent bythe pyloric valve F. The device 10 includes at least one internalpassageway or lumen 35 extending through the body 30, wherein thepassageway 35 receives and allows for the passage of chyme from thestomach C to the duodenum B. Referring to FIG. 3, the internalpassageway 35 extends from an end wall 16 of the first bulb 15 throughthe intermediate portion 25 and to an end wall 21 of the second bulb 20.Further, the passageway 35 includes a first end 35 a aligned with anopening 16 a in the end wall 16, and a second end 35 b aligned with anopening 21 a in the end wall 21. In a preferred embodiment of the weightcontrol device 10, the passageway 35 represents the longitudinal axis ofthe body 30. The internal passageway 35 is defined by two substantiallyparallel walls 36 that are spaced a distance apart to define a cavity37. In the embodiment of FIG. 12, the body 130 includes a first internalpassageway 135 and a second internal passageway 136 extending betweenthe end wall 116 of the first bulb 115 and the end wall 121 of thesecond bulb 120, and through the intermediate portion 125. Thus, thefirst and second passageways 135, 136 provide the body 130 with twoconduits for the passage of chyme from the stomach C to the duodenum B.In a slight variation of the body 130, the first and second internalpassageways 135, 136 may converge, such as aft of the intermediateportion 125, to define a common exit passageway in the second bulb 120.

When the weight control device 10 is implanted and inflated to define aninstalled or use position P1 (see FIG. 1), an exterior surface 17 of thefirst bulb 15 engages an inner surface of the pyloric antrum D. Thus,the first bulb 15 resides between the stomach corpus G (the central bodyportion of the stomach) and the pyloric valve F. In the use position P1,the first bulb 15 effectively seals the pyloric antrum D to prevent thenormal flow of chyme from the stomach B into the pyloric valve F andforces or directs chyme into the internal passageway 35. Because thebody 30 is inflatable, the dimensions of the first bulb 15 can becustomized during inflation to match the dimensions of the pyloricantrum D to facilitate sealing engagement between the bulb surface 17and the inner surface of the pyloric antrum D. This sealing engagementresults in a gastric outlet obstruction 19 (see FIG. 1) that causeschyme to accumulate proximate the first bulb 15 prior to entering theinternal passageway 35. The obstruction also prevents chyme fromdeparting the pyloric antrum D and as a result, chyme must pass throughthe internal passageway 35 to exit the stomach. As a result of theengagement, the first bulb 15 provides a gastric outlet obstruction 19in the stomach C that (i) prevents the normal passage of chyme from thestomach C through the pylorus; (ii) redirects chyme into the passageway35; and, (iii) reduces the volumetric capacity of the stomach C therebycausing the patient to feel satiated or “full” after consuming a reducedamount of food. Lastly, the engagement between the first bulb 15 and thepyloric antrum D retains the body 30 in the use position P1 such thatthe properly inflated first bulb 15 cannot pass beyond the pyloric valveF and into the duodenum B. As shown in FIG. 1, the first bulb 15 hasexterior dimensions that exceed the dimensions of the pyloric valve Fwhereby the first bulb 15 is prevented from passing beyond the valve Fand into the duodenum B. In a preferred embodiment of the device 10, afirst interface region or shoulder 18 (see FIGS. 1-3) is defined betweenthe first bulb 15 and the intermediate portion 25. The interface region18 has a tapered, annular configuration and engages the pyloric antrum Dadjacent to the pyloric valve F. In the use position P1, the first bulb15 has a diameter D1 that is 4-9 centimeters (cm), and preferably thediameter D1 is 5-8 cm.

In the use position P1, an exterior surface 22 of the second bulb 20engages an inner surface of the pyloric canal E, wherein the second bulb20 resides between the duodenum Band the pyloric valve F. The engagementbetween the second bulb 20 and the pyloric canal E retains the body 30in the use position P1 such that the properly inflated second bulb 20cannot pass through the pyloric valve F and into the pyloric antrum D orstomach corpus G. Referring to FIG. 1, the opening 21 a in the end wall21 of the second bulb 20 is oriented such that chyme discharged from thepassageway 35 is directed into the duodenum B. In a preferred embodimentof the device 10, a second interface region or shoulder 23 (see FIGS.1-3) is defined between the second bulb 20 and the intermediate portion25. The interface region 23 has a tapered, annular configuration andengages the pyloric canal E adjacent to the pyloric valve F. Onceinflated and implanted within a patient, the second bulb 20 has adiameter D2 that is 2-5 cm and preferably the diameter D2 is 3-4 cm.Also in the use position P1, an exterior surface 26 of the intermediateportion 25 engages an inner surface of the pyloric valve F, wherein thefirst bulb 15 engages the pyloric antrum B and the second bulb 20engages the pyloric canal E. Described in a different manner, thepyloric valve F contracts about the intermediate portion 25. In theembodiment where the intermediate portion 25 is semi-rigid, thecontraction of the pyloric valve F does not cause the intermediateportion 25 or the internal passageway 35 to completely collapse. In theuse position P1, the intermediate portion 25 has a diameter D3 that is1.0-2.5 centimeters, and preferably the diameter D3 is 1.5-2.0 cm. Dueto the configuration of the body 30, the intermediate diameter D3 isless than both the first bulb diameter D1 and the second bulb diameterD2. The internal passageway 35 has a diameter D4 that is 1-6 millimeters(mm), and preferably the diameter D4 is 2-4 mm.

FIG. 4 depicts the device 10 in a collapsed or un-inflated position P2,wherein the device 10 is flexible and ready to be implanted in a patientwith the use of an endoscope H. A valve assembly 40 that is used to fillthe device 10 with an inflation fluid, such as saline, extends from thefirst bulb 15. The valve assembly 40 includes a stem 45 that is graspedby the endoscope H (see FIGS. 5 and 6) during the implantation process,a valve body 50, and a fill tube segment 55 that can be severed afterthe device reaches the installed position P1. The valve body 50 has aninternal, one-way valve that accepts the inflation fluid supplied by theendoscope H. Over time, the body 30 may require additional inflationfluid due to seepage or leakage. Alternatively, the valve body 50 has atwo-way valve that allows for both the filling and removal of inflationfluid from the body 30. Preferably, the valve assembly 40 extends atoff-center location from the first bulb 15 because the internalpassageway 35 occupies the central axis of the body 30. In the eventthat the passageway 35 is not centrally located in the body 30, thevalve assembly 40 should be offset from the passageway 35. In anotherembodiment, the body 30 includes an internal valve assembly 65 (see FIG.7) that extends inward from an outer surface of the first bulb 15. Likethe valve assembly 40 of FIGS. 1-6, the assembly 65 includes a valvebody 66 and an internal stem 67. As shown in FIG. 2, the body 30includes a plurality of radio opaque markers 60 that facilitatedetection of the device 10 during testing subsequent to implantation.The counter the acids in the stomach A and to ensure a sufficient lifeof the body 30, the device 10 can be fabricated from one or more of thefollowing materials: fluoropolymer, such as PTFE(polytetrafluoroethylene), PFA (perfluoroalkoxy polymer resin), FEP(fluorinated ethylene-propylene) or polyethylene, such as HDPE (highdensity polyethylene), MDPE (medium density polyethylene) or LDPE (lowdensity polyethylene).

FIG. 5 depicts an intermediate position P3 where the collapsed device 10has been inserted through the stomach C and into the pylorus A by theendoscope H. The collapsed device 10 is inserted through the patient'smouth and through both the esophagus and stomach with the endoscope H.The endoscope H has a clamp I that grasps a groove 46 of the stem 45 tofacilitate insertion of the device 10. In the intermediate position P3,the first bulb 15 resides within the pyloric antrum D, the second bulb20 resides within the pyloric canal, and the intermediate portion 25resides within the pyloric valve F. A filling tube J within theendoscope H supplies an inflation fluid, such as saline, through thevalve 50 and into the body 30 until an inflated position P4 (see FIG. 6)is reached. Since the body 30 is an enclosed vessel, the inflation fluidfills the first bulb 15, the second bulb 20 and the intermediate portion25 to inflate the body 30. In the inflated position P4, the endoscope His coupled to the inflated body 30, wherein the exterior surface 17 ofthe first bulb 15 engages an inner surface of the pyloric antrum D, theexterior surface 22 of the second bulb 20 engages an inner surface ofthe pyloric canal E, and the exterior surface 26 of the intermediateportion 25 engages an inner surface of the pyloric valve F. Thus, in theinflated position P4, the device 10 is inflated such that the first bulb15 engages the pyloric antrum B and the second bulb 20 engages thepyloric canal E, both adjacent the pyloric valve F. After the inflatedposition P4 is reached, the endoscope H is de-coupled from the valveassembly 40 and removed from the patient whereby the device 10 is readyfor use. To remove an implanted device 10, the body 30 is deflated, suchas by piercing the first bulb 15, and the endoscope H is used to removethe deflated body 30.

After the device 10 has been implanted and is in the use position Pl,the device 10 provides a method of treating obese patients. The methodcomprises the sequenced implantation of devices 10 having differentsized passageways 35 to counter the digestive tract's accommodation ofan implanted device 10. In a first treatment step, a first device 10having the internal passageway 35 with a diameter D4, such as 4.0millimeters, is implanted within the patient's pylorus A at the useposition P1. Thus, the first bulb 15 provides a gastric outletobstruction 19 in the stomach C that blocks the normal passage of chymefrom the stomach C and that redirects chyme into the passageway 35. Theresulting gastric outlet obstruction 19 reduces the volumetric capacityof the stomach C thereby causing the patient to feel “full” resulting inappetite suppression, after consuming a reduced quantity of food.Initially, the patient will feel full and stop consuming food or reducethe rate of food consumption, which will lead to an initial phase ofweight loss during the first treatment step. However, over time, thepatient's digestive tract will adapt to the first device 10, the patientwill not feel full after consuming a similar quantity of food, and theweight loss experienced during the initial phase will stagnate.

A second treatment step is designed to combat the stagnation in weightloss experienced during the first step by using a different-sized seconddevice 10 in place of the first device 10. Specifically, the firstdevice 10 is removed from the patient and replaced by the second device10 which has an internal passageway 35 with a reduced diameter D4, suchas 3.0 mm. Thus, the passageway diameter D4 of the second device 10 isless than that of the first device 10 and the volume of the passageway35 is reduced as well. While the second device 10 continues to provide agastric outlet obstruction 19 in the stomach C that blocks the normalpassage of chyme from the stomach C and that redirects chyme into thepassageway 35, the passageway 35 has reduced dimensions that reduce thevolume of chyme that may pass through the device 10. Because less chymeis able to pass through the passageway of the second device 10 comparedto the passageway of the first device 10, a greater amount of chymeaccumulates within the stomach C leading the patient to feel full andstop consuming food. This will lead to weight loss during the earlyphase of the second treatment step, however, the patient's digestivetract will adapt to the second device 10 over time. Accordingly, thepatient will not feel full after consuming a similar quantity of food,and the weight loss experienced during the early phase will againstagnate.

To combat the stagnation in weight loss experienced during the secondstep, a third treatment step involves replacing the second device 10with a different-sized third device 10. Specifically, the second device10 is replaced by the third device 10 which has an internal passageway35 with a further reduced diameter D4, such as 2.0 mm. Thus, thepassageway diameter D4 of the third device 10 is less than that of boththe first and second devices 10. Like the first and second devices 10,the third device 10 provides a gastric outlet obstruction 19 in thestomach C that blocks the normal passage of chyme from the stomach C andthat redirects chyme into the passageway 35. Due to the reduced diameterD4, the passageway 35 accepts an even smaller volume of chyme fortransmission through the pylorus A and to the duodenum B. Because lesschyme is able to pass through the passageway 35 of the third device 10compared to the passageway 35 of both the first and second devices 10,an even greater amount of chyme accumulates proximate the first bulb 15and within the stomach C leading the patient to feel full and stopconsuming food.

Assuming the same quantity of food is consumed in the same time intervalwith each of the three different sized devices 10, a greater amount ofchyme is transmitted through the passageway 35 of the first device 10compared to either of the second or third devices 10. Also, a greateramount of chyme is transmitted through the passageway 35 of the seconddevice 10 compared to the third device 10. Under these same conditions,the quantity of chyme obstructed by the bulb 15 and accumulating withinthe stomach corpus G is greater for the third device 10 compared to thesecond device 10, and greater for the second device 10 compared to thefirst device 10. Therefore, the present invention provides a method oftreating obesity with the implantation of devices 10 having differentsized internal passageways 35 which reduce the volume of thyme passingthrough the body 30, increase the accumulation of chyme within thestomach C, and hasten the patient to feel full and reduce or halt foodconsumption. Because this method of treatment counters the digestivetract's natural tendency to accommodate a single device 10, the patientshould continue to experience weight loss.

A second obesity treatment method is shown in FIGS. 8-11 and involvesthe use of removable inserts 70 of variable dimensions in the passageway35 to counter the digest tract's accommodation of the device 10. In afirst stage of the treatment method, the device 10 is implanted withinthe patient's pylorus A. Consistent with that explained above, the firstbulb 15 provides a gastric outlet obstruction 19 in the stomach C thatblocks the normal passage of chyme from the stomach C and that redirectschyme into the passageway 35 for transmission to the duodenum B. Whenthe patient's digestive tract begins to accommodate the device 10 andweight loss stagnates, the second stage of the treatment methodcommences. Instead of replacing the existing device 10 with a device 10having a smaller passageway 10, the second stage involves the insertionof a first insert 70, with the endoscope H, into the passageway 35 ofthe existing, implanted device 10 (see FIGS. 8 and 9). Since the device10 is already inflated, the passageway 35 slidingly receives the firstinsert 70. The first insert 70 includes opposed end flanges 71 whichengage the outer surfaces 16, 21 of the first and second bulbs 15, 20,respectively, to further secure the position of the insert 70 within thepassageway 35. As mentioned above, the passageway 35 has a diameter D4and the first insert 70 has a diameter D5 that is less than thepassageway diameter D4. For example, the passageway diameter D4 is 5 mmand the first insert diameter D5 is 4 mm. The insert 70 has a wallarrangement 72 with a thickness that provides the insert diameter D5.Due to its reduced dimensions, the first insert 70 effectively reducesthe volume of the passageway 35 which restricts the amount of chyme thatmay pass through the device 10 and which increases the accumulation ofchyme within the stomach C, leading the patient to feel full and stopconsuming food.

A second treatment stage is designed to combat the stagnation in weightloss experienced during the first stage by removing the first insert 70and inserting a second insert 75 into the passageway 35 with anendoscope H. As shown in FIG. 10, the second insert 75 has a diameter D6that is less than both the passageway diameter D4 and the first insertdiameter D5. For example, the passageway diameter D4 is 5 mm, the firstinsert diameter D5 is 4 mm, and the second insert diameter D6 is 3 mm.The second insert 75 has an end flange 76 and a wall arrangement 77 witha thickness that provides the insert diameter D6. Like the first insert70, the second insert 75 effectively reduces the volume of thepassageway 35 which thereby restricts the amount of chyme that may passthrough the device 10 and into the duodenum B. This restrictionincreases the accumulation of chyme within the stomach C, leading thepatient to feel full and stop consuming food. To offset the stagnationin weight loss that may result in the second stage, a third treatmentstage involves using the endoscope H to replace the second insert 75with a third insert 80 in the passageway 35. Referring to FIG. 11, thethird insert 80 has a diameter D7 that is less than the passagewaydiameter D4 and both the first and second insert diameters D5, D6. As anexample, the passageway diameter D4 is 5 mm, the first insert diameterD5 is 4 mm, the second insert diameter D6 is 3 mm, and the third insertdiameter D7 is 2 mm. The third insert 80 has an end flange 81 and a wallarrangement 82 with a thickness that provides the insert diameter D7.Like the first and second inserts 70, 75, the third insert 80effectively reduces the volume of the passageway 35 which therebyrestricts the amount of chyme that may pass through the device 10 andinto the duodenum B for appetite suppression purposes.

Each of these methods provide sequenced protocols for treating obesitywith the device 10. Because the device 10 is easy to implant, eithertreatment method may be utilized during an office visit withoutrequiring a costly and time-consuming hospital visit for the patient.Once sufficiently inflated, the resulting obstruction causes chyme toaccumulate proximate the first bulb 15 or to entering the internalpassageway 35 where it is then transported through the inflatable body35 and discharged from the second bulb 20 into the patient's duodenum B.The accumulation of chyme in the pyloric antrum D and the stomach Acauses the patient to feel full and stop eating. Thus, these treatmentmethods provide a gastric outlet obstruction 19 that slows the passageof chyme into the duodenum B and as a result, the patient feels full andstops eating after consuming relatively small portions. Due to thesequenced nature of the first and second treatment methods, the gastricoutlet obstruction 19 counteracts the stomach's attempt to accommodatethe device 10 over time.

Numerous modifications may be made to the foregoing invention withoutdeparting from the basic teachings thereof. Although the presentinvention has been described in substantial detail with reference to oneor more specific embodiments, those of skill in the art will recognizethat changes may be made thereto without departing from the scope andspirit of the invention.

What is claimed is:
 1. An endoscopically implantable weight controldevice that forms a gastric outlet obstruction in a patient's digestivetract, the weight control device comprising: an inflatable body residingbetween the patient's stomach and duodenum, the body having: a firstbulbous potion; a second bulbous portion, the exterior dimensions of thefirst bulbous portion exceeding the exterior dimension of the secondbulbous portion; an intermediate portion with exterior dimensions lessthan the exterior dimensions of both the first and second bulbousportions, wherein the intermediate portion resides within the patient'spyloric valve when the device is implanted; and, an internal passagewayextending through the body, wherein the passageway receives and allowsfar the passage of chyme from the stomach to the duodenum.
 2. Theimplantable weight control device of claim 1, wherein an exteriorsurface of the first bulbous portion engages an inner surface of thepyloric antrum.
 3. The implantable weight control device of claim 1,wherein an exterior surface of the intermediate portion engages an innersurface of the pyloric valve.
 4. The implantable weight control deviceof claim 1, wherein an exterior surface of the second bulbous portionengages an inner surface of the pyloric canal.
 5. The implantable weightcontrol device of claim 1, wherein the transition from the first bulbousportion to the intermediate portion defines a first interface regionthat engages the terminal portion of the stomach prior to the pyloricvalve.
 6. The implantable weight control device of claim 1, wherein thefirst bulbous portion includes a valve assembly that allows for thefilling of the inflatable body.
 7. The implantable weight control deviceof claim 6, wherein the valve assembly includes a stem that is graspedby an endoscope during implantation of the device.
 8. The implantableweight control device of claim 1, wherein the internal passagewayextends from an end wall of the first bulbous portion through theintermediate potion and to an end wall of the second bulbous portion. 9.A weight control device that is implantable with an endoscope and thatforms a gastric outlet obstruction in a patient's digestive tract, theweight control device comprising: an inflatable body having a firstbulb, a second bulb with a circumference less than a circumference ofthe first bulb, and an intermediate portion, wherein the intermediateportion resides within the patient's pyloric valve when the device isimplanted; the body further having at least one internal passagewayextending through the first and second bulbs; and, wherein chyme exitingthe patient's stomach passes through the internal passageway to reachthe duodenum.
 10. The weight control device of claim 9, wherein thefirst bulb defines an obstruction that prevents chyme, other than thatpassing through the internal passageway, from reaching the pyloric valveand the duodenum.
 11. The weight control device of claim 9, whereinfirst bulb engages an inner surface of the stomach proximate the pyloricvalve to prevent the firs bulb from moving past the pyloric valve andinto the duodenum.
 12. The weight control device of claim 11, whereinthe intermediate portion engages an inner surface of the pyloric valve.13. The weight control device of claim 11, wherein the second bulbengages an inner surface of the pyloric canal proximate the pyloricvalve.
 14. The weight control device of claim 9, wherein the body has adumbbell configuration, wherein the transition from the first bulb tothe intermediate portion defines a first annular shoulder that engagesthe terminal portion of the stomach prior to the pyloric valve.
 15. Theweight control device of claim 9, wherein the first bulb includes a stemassembly that is grasped by an endoscope during implantation of thedevice, wherein the stem assembly includes a valve for filling of theinflatable body.
 16. The weight control device of claim 9, wherein theinternal passageway extends from an end wall of the first bulb throughthe intermediate portion and to an end wall of the second bulb.
 17. Theweight control device of claim 9, further comprising a first insert thatis removably inserted within the internal passageway, the first inserthaving a diameter that is less than a diameter of the internalpassageway.
 18. The weight control device of claim 17, furthercomprising a second insert that is removably inserted within theinternal passageway, the second insert having a diameter that is lessthan the diameter of both the first insert and the internal passageway.19. An endoscopically implantable weight control device that forms agastric outlet obstruction in a patient's digestive tract, the weightcontrol device comprising: an inflatable body having a first bulb, asecond bulb, and an intermediate portion that resides within thepatient's pyloric valve; the inflatable body further having at least oneinternal passageway extending between an end wall of the first bulbthrough the intermediate portion and to an end wall of the second bulb,wherein the passageway receives and allows for the passage of chyme fromthe stomach to the duodenum.
 20. The weight control device of claim 19,wherein the weight control device is implanted with an endoscope in thepatient's digestive tract in a deflated state, and then inflated suchthat the first bulb engages an inner surface of the stomach proximatethe pyloric valve and the intermediate portion engages an inner surfaceof the pyloric channel.
 21. The weight control device of claim 19,further comprising: a first insert that is removably inserted within theinternal passageway, the first insert having a diameter that is lessthan a diameter of the internal passageway; and, a second insert that isremovably inserted within the internal passageway, the second inserthaving a diameter that is less than the diameter of both the firstinsert and the internal passageway.
 22. The weight control device ofclaim 19, wherein the inflatable body has a pair of internal passagewaysextending from the end wall of the first bulb through the intermediateportion and to the end wall of the second bulb, wherein the passagewaysreceive chyme from the stomach to the duodenum.